Antioxidant activity of supramolecular water-soluble fullerenes evaluated by beta-carotene bleaching assay

We investigated the antioxidant activity of supramolecular water-soluble fullerenes, polyvinylpyrrolidone (PVP)-entrapped C(60), and gamma-cyclodextrin (CD)-bi-capped C(60), based on comparable beta-carotene bleaching assay. Antioxidant activity against reactive oxygen species (ROS) generated by three different methods, (i) autoxidation of linoleic acid, (ii) hydrogen peroxide promoter, and (iii) photoirradiation, was evaluated as percent of inhibition relative to a control experiment in view of the bleaching rate constant (k(obs)) as well as the persistent absorbency of beta-carotene. Water-soluble fullerenes exhibit significant inhibitory effects on the oxidative discoloration of beta-carotene in any system.     

Characterization of specific binding sites for a mitogenic sulfated peptide, phytosulfokine-alpha, in the plasma-membrane fraction derived from Oryza sativa L.

Treatment of rice cells with an endogenous mitogenic peptide, phytosulfokine-alpha (PSK-alpha), results in cell proliferation. In the present study, [3H]PSK-alpha prepared by catalytic reduction of a PSK-alpha analog containing tetradehydroisoleucine was employed to identify putative PSK-alpha target molecules on rice plasma membranes. Membrane binding of the ligand was found to be saturable, reversible and pH dependent. Scatchard analysis demonstrated the existence of both high- and low-affinity binding sites with Kd values of 1.4 nM and 27 nM, respectively. Competition studies with [3H]PSK-alpha and several PSK-alpha analogs showed that displacing activity closely corresponds to the ability to induce cell proliferation. The properties of the binding sites distributed on plasma membranes are consistent with the function of PSK-alpha receptors in activating a cascade of molecular events involved in plant cell proliferation.     

Effect of low pH on the morphology and viability of Cryptosporidium andersoni sporozoites and histopathology in the stomachs of infected mice

The genus Cryptosporidium includes many common parasites infecting animals and humans, and is a major cause of diarrheal illness worldwide. The biology of gastric Cryptosporidium spp., including replication in the stomach, has not been well documented. This study evaluated the viability of Cryptosporidium andersoni sporozoites in gastric environments after excystation and examined the endogenous development and histopathological changes in the stomachs of infected mice, using a novel type of C. andersoni. Sporozoites were affected by low pH (61.6% viability after 3h at pH2.0). Electron microscopy revealed developmental parasites on the gastric foveolae but not on the surface of the gastric mucosa. Histopathological examinations at 1, 2, 4 and 12 weeks p.i. uncovered three different lesions. The gastric mucosa of foveolae filled with parasites was extended and the amount of neutral mucopolysaccharide at the mucosal surface was decreased with the first type of lesion. The gastric mucosa was atrophied, some gastric glands were disrupted and the amount of acid mucopolysaccharide at the mucosal surface was increased with the second type. Finally, the gastric mucosa was slightly extended and goblet cells were present in the gastric mucosa, indicating intestinal metaplasia, in the third type. No parasites were detected in these areas with increased acidic mucin and indications of metaplasia. The results suggest that C. andersoni parasites could not survive in acidic environments for a long period before invading host cells and preferentially develop in neutral sites of the gastric mucosa, resulting in histopathological changes and chronic shedding of oocysts.     

Extremely divergent host plant acceptance with gene flow between sympatric host races of the phytophagous ladybird beetle Henosepilachna diekei

Ecological divergence alone can prevent the majority of gene flow in the absence of other forms of reproductive isolation. Although the importance of ecological divergence in promoting reproductive isolation has been broadly recognized, its net impact on speciation has rarely been estimated in the wild. The phytophagous ladybird beetle Henosepilachna diekei Jadwiszczak & Wegrzynowicz includes two sympatric host races that are reproductively isolated solely by extreme specialization to either of the host plants Mikania micrantha Kunth (Asteraceae) or Leucas lavandulifolia Sm. (Lamiaceae) in West Java, Indonesia. To investigate the impact of differential host use as an isolating barrier, we carried out adult host acceptance tests and molecular population genetic analyses based on mitochondrial ND2 and nucleic ITS2 gene sequences using 13 wild populations of the host races, including four sympatric population pairs. Almost all individuals of these host races persistently accepted only the original host plant. We detected restricted but a degree of gene flow between these host races. A migration event occurred only in very recent time compared to their divergence time, indicating recent secondary contact of these host races in the surveyed area. These results reveal the remarkably large impact of host‐plant shift over almost the entire process of speciation and illustrate that ecological divergence has been maintained even under the presence of a certain degree of gene flow.     

Identification of three potent hydroxyproline O‐galactosyltransferases in Arabidopsis

Arabinogalactan proteins (AGPs) are plant‐specific extracellular glycoproteins implicated in a variety of processes during growth and development. AGP biosynthesis involves O‐galactosylation of hydroxyproline (Hyp) residues followed by a stepwise elongation of the complex sugar chains. However, functionally dominant Hyp O‐galactosyltransferases, such that their disruption produces phenocopies of AGP‐deficient mutants, remain to be identified. Here, we purified and identified three potent Hyp O‐galactosyltransferases, HPGT1, HPGT2 and HPGT3, from Arabidopsis microsomal fractions. Loss‐of‐function analysis indicated that approximately 90% of the endogenous Hyp O‐galactosylation activity is attributable to these three enzymes. AGP14 expressed in the triple mutant migrated much faster on SDS‐PAGE than when expressed in wild‐type, confirming a considerable decrease in levels of glycosylation of AGPs in the mutant. Loss‐of‐function mutant plants exhibited a pleiotropic phenotype of longer lateral roots, longer root hairs, radial expansion of the cells in the root tip, small leaves, shorter inflorescence stems, reduced fertility and shorter siliques. Our findings provide genetic evidence that Hyp‐linked arabinogalactan polysaccharide chains are critical for AGP function and clues to how arabinogalactan moieties of AGPs contribute to cell‐to‐cell communication during plant growth and development.     

Psychometric Validation of the Japanese Version of the Neuropathic Pain Symptom Inventory

Objective

This study aimed to evaluate the validity and reliability of the Japanese version of the Neuropathic Pain Symptom Inventory (NPSI-J).

Design

Cross-sectional study design.

Subjects and Methods

The original Neuropathic Pain Symptom Inventory (NPSI) was translated into Japanese according to published guidelines. Subsequently, an observational study of 60 Japanese patients suffering from neuropathic pain was performed to evaluate the validity and reliability of the NPSI-J.

Results

The NPSI-J exhibited a statistically significant correlation with pain intensity (Numerical Rating Scale). The Cronbach alpha value for Likert items was 0.86. Using the test–retest analysis method, the intraclass correlation coefficient between the two scores was 0.81. Factor analysis revealed that the main component of NPSI-J comprised three determinative factors.

Conclusions

The NPSI-J is a reliable and valid pain assessment tool.